Hypoxia acts as an environmental cue for the human tissue-resident memory T cell differentiation program

Tissue-resident memory T cells (T-RM) provide frontline defense against infectious diseases and contribute to antitumor immunity; however, aside from the necessity of TGF-beta, knowledge regarding T-RM-inductive cues remains incomplete, particularly for human cells. Oxygen tension is an environmental cue that distinguishes peripheral tissues from the circulation, and here, we demonstrate that differentiation of human CD8(+) T cells in the presence of hypoxia and TGF-beta(1) led to the development of a T-RM phenotype, characterized by a greater than 5-fold increase in CD69(+)CD103(+) cells expressing human T-RM hallmarks and enrichment for endogenous human T-RM gene signatures, including increased adhesion molecule expression and decreased expression of genes involved in recirculation. Hypoxia and TGF-beta(1) synergized to produce a significantly larger population of T-RM phenotype cells than either condition alone, and comparison of these cells from the individual and combination conditions revealed distinct phenotypic and transcriptional profiles, indicating a programming response to milieu rather than a mere expansion. Our findings identify a likely previously unreported cue for the T-RM differentiation program and can enable facile generation of human T-RM phenotype cells in vitro for basic studies and translational applications such as adoptive cellular therapy.

Automated summary

The combination of hypoxia and TGF-beta(1) can induce the development of a T-RM phenotype in human CD8(+) T cells, leading to specific phenotypic features and enrichment of human T-RM gene signatures. This finding suggests a previously unreported cue for the T-RM differentiation program, offering potential applications in adoptive cellular therapy and basic research.